This application relates in general to an improved drive for a tire lift mechanism, and also to a simplified method of assembling such mechanisms.
It is known to store a spare tire at the underside of a vehicle, particularly in vans. Tire lift mechanisms are typically utilized for raising and lowering the spare tire from beneath the vehicle. A cable extends from the lift mechanism and a rotative drive is arranged upon a first axis for lowering and raising the cable, to raise and lower the spare tire. An access opening may be formed through the rear of the vehicle body, and a tool such as a jack handle may be inserted through the access opening and used to raise and lower the cable.
One particularly successful example of such a mechanism is disclosed in U.S. Pat. No. 4,915,358. A drive tube is selectively driven by a tool for raising and lowering a cable. The drive tube is rotatably received in a bearing formed beneath the underside of a vehicle, and drives a driven shaft, which is connected to the actual drive for the cable. The connection between the drive tube and the driven shaft is a universal-type connection wherein the drive tube has a plurality of circumferentially-shaped drive pins received in slots in the driven shaft. The drive pins may pivot relative to the slots such that the axis of rotation of the drive tube may be at an angle relative to the axis of rotation of the driven shaft. This facilitates the use of the assembly, such that a user need not bend to a low vertical position to raise and lower the tire.
Although the above-discussed patented mechanism has proven successful, several improvements may still be made. The universal connection of the drive tube to the driven shaft includes a radially outwardly disposed cup. This cup may retain water, which may freeze, locking the connection. Further, the connection between the drive tube and the driven shaft may result in undesirable rattling and looseness. Lastly, it is somewhat difficult to mount the tire lift mechanism to the underside of a vehicle, and then position the drive tube through its bearing mount. These three area are improved in the present invention.